Investigation of the magnetism in thin single Ho(00.1) films via neutron reflectivity measurements

Resonant magnetic X-ray scattering studies have been carried out recently to explore the phase transition and NeH el temperature for the helical spin structure in single Ho "lms as a function of "lm thickness. However these experiments have a natural limit of about 200 As , since with decreasing "lm thickness leaking charge scattering and "nite thickness oscillations bury the magnetic satellite peaks. This limit hinders the investigation of scaling e!ects. Using neutron scattering we could now show that the intensity of the (00.2!q) and (00.0#q) magnetic satellite re#ections are surprisingly large, allowing to explore the phase transition in epitaxial Ho(00.1) "lms down to below 50 As . ( 2000 Elsevier Science B.V. All rights reserved.